



Book 



.0.^ 




f J^y**%i'**" 






REPORT 



IMPORTATION OF PARASITES 



PREDACEOUS INSECTS, 



STATE BOARD OF HOETIOULTURE. 



IN ACCORDANCE WITH AN ACT OF THE LEGISLATURE, APPROVED 

MARCH 31, 1891. 




SACRAMENTO: 

STATE OFFICE, : : : : : a. j. Johnston, supt. state printing. 

1892. 






BENEFICIAL INSECTS. 



Plate 1 




NEWLY INTRODUCED SPECIES. 



' 5.CP0CK£K COMPANV ItTM- i t 



BENEFICIAL INSECTS. 

SPECIES OF RECENT INTRODUCTION. 
[Explanation of Plate.] 

1. Orcus chcdyheus, Boisd.; female enlarged. 
la. Head and prothorax of male; enlarged. 
15. Natural size. 

2. Orcus australasia, Boisd.; female enlarged. 
2a. Natural size. 

3. Novius Koebelei, OllifF.; male enlarged. 
3a. Male; natural size. 

3&. Female; natural size. 
3c. Larva; enlarged. 
Sd. Larva; natural size. 

4. Shows branch with Cottony Cushion Scale, and larva of Novius 
Koebelei. 

4a. Cottony Cushion Scale. 

4b. Shows larva of Novius Koebelei (natural size), preying upon Cot- 
tony Cushion Scale. 

5. Leis conformis, Boisd.; female enlarged. 
5a. Male; natural size. 

5b. Female; natural size. 

6. Thalpochares coccophagus, Myer; enlarged. 
6a. Natural size. 



REPORT 



IMPORTATION OF PARASITES 



PREDACEOUS INSECTS, 

' BY THE 

STATE BOARD OF HORTICULTURE. 



IN ACCORDANCE WITH AN ACT OF THE LEGISLATURE, APPROVED 

MARCH 31, 1891. 




SACRAMENTO: 
STATE OFFICE, : : : : : A. J. Johnston, supt. state printing. 

1892. 



.^0,^- 



^ 

\ 

^ 



^ 






REPOKT. 



To Hon. H. H. Markham, Governor, and to the honorable the Legislature 
of California: 

In accordance with an Act (Chapter CXCIV, Laws of 1891) entitled 
''An Act to appropriate $5,000 for the purpose of sending an expert to 
Australia, New Zealand, and adjacent countries, to collect and import 
into this State parasites and predaceous insects," approved March 31, 
1891, we beg to submit the following report: 

Soon after the passage of this Act we applied to the Secretary of Agri- 
culture at Washington, D. C, to aid us in this investigation by sending 
on this mission Mr. Albert Koebele, an accredited agent of that depart- 
ment, and who, on a former mission, discovered the Vedalia cardinalis. 
We also requested that his salary be met by that department, we assum- 
ing to pay his expenses. This the Secretary consented to do, and on 
August 20, 1891, Mr. Koebele sailed for Australia, where he remained 
about a year. As to what was accomplished, we beg to refer you to his 
report and to the report of the Entomologist of this Board, which are 
herewith appended. 



6 REPORT ON PARASITES AND PREDACEOUS INSECTS. 

AMOUNT EXPENDED. 

The following are the expenditures incurred; all vouchers and item- 
ized bills are on file in the office of the State Controller: 

1891— Oct. 31— Voucher No. 1 $395 25 

Oct. 31— Voucher No. 2 380 68 

Nov. 30— Voucher No. 3 313 43 

Dec. 28— Voucher No. 4 236 87 

1892— Jan. 25— Voucher No. 5 297 54 

Feb. 29— Voucher No. 6 312 00 

Mar. 21— Voucher No. 7 297 47 

Apr. 25— Voucher No. 8 365 52 

Aug. 4— Voucher No. 9 918 12 

Sept. 26— Voucher No. 10 131 65 

Cost of transmitting funds — 

Voucher No. 11 24 75 

Voucher No. 12 10 00 

Voucher No. 13 15 00 

Voucher No. 14 13 90 

Cost of illustrating report— Voucher No. 15 625 00 

Total $4,337 18 

Balance unexpended 662 82 

This amount has been returned to the State Treasurer, as is shown 
by certificate from Controller's office, No. 163. 

Our thanks are especially due to Hon. J. M. Rusk, Secretary of Agri- 
culture, and to all who rendered us assistance in this research. 
Very respectfully, 

ELLWOOD COOPER, 
L. W. BUCK, 
FRANK A. KIMBALL, 
J. L. MOSIIER, 
A. BLOCK, 
FRED. C. MILES, 
SOL. RUNYON, 
I. H. THOMAS, 
A. F. WHITE, 

Commissioners. 
B. M. Lelong, 

Secretary and Chief Horticultural Officer. 

San Francisco, Cal., December 5, 1892. 



REPORT ON PARASITES AND PREDACEOUS INSECTS. 



EXPERTS TRIP TO FOREIGN COUNTRIES. 



NEW SPECIES INTRODUCED. 

To Hon. Ellwood Cooper, President, and to the honorable State Board 
of Horticulture: 

Sir: At your request I give herewith some notes on the condition of 
fruit trees and the coccids injurious thereto in Australia, also the work 
of natural parasites upon the same in that country, as found during my 
recent mission; at the same time giving you a statement as to how I 
found the recently introduced species on my trip to Los Angeles and 
Santa Barbara at the beginning of September, 1892, and my opinion of 
their future work in this country. 

My report upon this last trip has been forwarded to the Secretary of 
Agriculture, to whom I had to report as directed in letter of authoriza- 
tion, dated May 29, 1891. In it I give a full account of all the beneficial 
insects found and forwarded to this country, as also of such as were 
studied in the field, and which may be introduced at some future time. 
As this report will not appear in print until some time during 1893, I 
will briefly acquaint you with what was accomplished. 

As you are aware, my chief work was to search for such parasitic 
and predaceous insects as prey upon the coccids injurious to our fruit 
trees. These are the so-called red scale (Aspidiotus aurantii, Mask.), 
detrimental to our orange trees; the pernicious scale {Aspidiotus perni- 
ciosus, Comst.), upon and destructive to various deciduous trees; and the 
various black scales {Lecanium) , as the principal species. 

The red scale is present all over Australia upon citrus and various 
other trees and shrubs, and has been knowai upon orange trees for the 
last fifty years. Whether the insect is a native or introduced cannot 
be said with any certainty, but as the conditions indicate. I think it is 
an introduced species. Internal parasites could rarely be found upon 
the same; chiefly upon the male scales, small holes were occasionally 
found, from whence minute chalcid flies had issued. None of these 
were bred. 

The black scales are represented by various species, and our most 
common forms, Lecanium olere, Bernard, and L. hesjieridum, Linn., are 
found everywhere in New Zealand and Australia, and in my opinion 
are indigenous to the latter country. Numerous internal parasites were 
found preying upon these two coccids, and were repeatedly sent here. It 
is in predaceous insects feeding upon the various coccids that Australia 
is immensely rich, and these are chiefly ladybirds {Coccinellidse). 

The group Orcus resembles our own form Chilocorus, of which C. 
hivtdnerus is well known in California. The habits are the same; they 
will breed upon a variet}- of scales from early spring until winter, when 
the mature insects will hibernate for a time. Four species of these were 
sent here, and two of them, 0. chalybeus and 0. australasia, in very 



8 REPORT ON PARASITES AND PREDACEOUS INSECTS. 

large numbers. Cryptoleemus was found in two forms, C Montrouzieri 
and C. australis. The larva3 of these are peculiar, as they are covered 
above with contiguous, white, mealy, secreted appendages; they feed 
chiefly upon mealy bugs (Dactylopius). The first named species, which 
was sent here in large numbers, is also doing good work in feeding upon 
the various black scales. 

Bucolus is closely related to Cryptolxmus, and two forms were sent 
here. Probably the most valuable of all the scale-feeding Coccinellidx 
are the Rhizobiids. This group is very largely represented in Australia, 
and only a few forms are reported from other parts of the world. 
America had none previous to this importation. The insects are closely 
related to our Scymnids, but some of the species are much larger. They 
feed upon all sorts of scales, and their larvse were found at all times 
during the year in Australia. Some fifteen species, nearly all unknown 
to science, were sent here. 

Scymnodes also resembles Rhozobius; but one species, S. Koebelei, Black- 
burn, and a variety of the same, named varijws, were sent here. These 
are expected to feed upon black scales and Chionaspids. Erithionyx is 
quite a large black beetle covered with short, yellowish-brown hairs; 
the one species, E. lanosus, was found feeding on Chionaspis, upon orange 
trees infested with black scale, and was repeatedly sent here. These 
species were liberated by j^ou upon Lecanium. 

Scymnus is known to almost every one; we know the value of our 
S. marginicollis in California, and the good work it is able to do upon a 
variety of scales. I have so far eight species named from Australia 
and a number from New Zealand, which were sent here. These can be 
expected to feed upon most of our coccids. 

Mydus resembles a Scymnid, and M. pygmiieus, feeding upon mealy 
bugs, was sent here; and there are a number of groups of small, 
roundish Coccinellidx, of which Gymnoscyvinus, Cycloscymus, Libernes, 
Cyreme, and Serangium, found upon a variety of coccids, were sent 
here. 

As to the aphis-feeding Coccinellidx, all the species that could be 
obtained were collected and forwarded. Some of these will not only 
feed upon plant-lice, but will also live upon scale insects. Coccinella 
antijwdum has only been found by me to prey upon scales in New Zea- 
land. Coccinella arcuata was found in southern Queensland feeding 
upon the orange aphis, but on the Richmond River, New South Wales, 
the same insect was feeding upon Lecanium filicum on a fern, and again 
at Levuca, Fiji, it was feeding upon an Aleurodes on taro leaves. Leis 
conformis, which feeds on jilant-lice, will, after these have all disap- 
peared, begin its destructive work upon the woolly aphis, of wliich it 
cleans whole orchards, as observed in South Australia and Victoria. 

In all, some forty thousand specimens of ladvbirds were collected by 
me during this last trip, and forwarded to California, and I can say pos- 
itively that no mistake was made in sending anything but beneficial 
insects. 

It was timely discovered that nearly all the larvse of the ladybirds in 
Australia are preyed upon by parasites, in certain instances almost 
destroying all of these. The pupse are also preyed upon by chalcid 
parasites, and in consequence only the mature insects were sent, thus 
leaving all their enemies behind, and we shall thereby have the benefit 
of the work of these insects without the detriment of the parasites prey- 
ing upon them. 



REPOKT ON PARASITES AND PREDACEOUS INSECTS. 9 

One of the best enemies to the black scale in Australia is the larva of 
a small moth ( Thal/pochares), which builds itself a house, so to speak, by 
spinning together the remains of the eaten-out scales, etc. With this 
protection against its enemies, it is able to walk over the tree, and thus 
devours large numbers of the scales daily. The transformations of this 
insect have not been closely studied in the field, but from what I have 
seen must be very rapid, especially in warm weather; and as full-grown 
larvse were found upon the same tree about every two weeks, it will take 
at the most four weeks from egg to mature insect during summer. When 
full grown the larva spins most anywhere on the tree, but prefers any 
crevice on branches or trunk of tree, between the forks, and also on the 
ground at the base of stem. According to the season or circumstances, 
they may pupate at once or remain for several months, and in no case 
should they be disturbed in any way, for if taken out of their cocoon they 
will rarely be able to spin another and will invariably perish. Two 
species were found in Australia, and one at least is introduced and 
established. 

The trunks and branches of citrus trees in Australia are often covered 
with fine, silky we))S interwoven with remains of scales, and under this 
are found numerous larvse of a small Tineid moth that devour the 
coccids thereon. These latter are chiefly Chionaspis citri and Mytilaspis 
Gloverii. Efforts are now being made to introduce this valuable little 
moth here, and a number were liberated upon trees infested with the 
pernicious scale. 

Aside from the numerous parasites and predaceous insects destructive 
to scale insects in Australia, there exist several species of fungoids 
detrimental to various coccids. Microcera coccophilla, if once started 
upon a tree infested with the red scale, will keep on spreading until all 
the scales are destroyed. The same may be said of the fungi living at 
the expense of the black scales. I have had a number of small orange 
trees infested with Lecanhim^ on which also were ants that kept away 
the natural enemies — upon which the Thalpocharef< larvae were collected 
regularly, as these with their protecting armor are quite safe here — on 
some of which the fungus began to spread until every black scale 
upon the trees was destroyed. The fungus will apparently only grow 
during damp weather, and I shall try it in the early spring. If once 
started this could easily be disseminated. 

The condition of the olive trees, as observed in South Australia, is 
fairly good. Some of these are more or less infested with black scale 
(Lecanium cassinise, Mask.), but notwithstanding this, trees seen on a 
hillside, growing wild, so to speak, were loaded with fruit and but few of 
the trees had scales in quantity. It was at a time when everything was 
completely dry that I visited South Australia, and the predaceous 
insects found feeding upon these scales may not be all that prey upon 
them at other times of the year. The species found in larva, pupa, and 
imago state upon olive were Rhizobius hirtelhts, R. cxcus, and Cyreme 
nigellum. The first-named species was present in very large numbers, 
and was found upon various scales in New South Wales, as also other 
coccids. Both the larvse and pupre of the Rhizobiids were found 
destroyed in large numbers by parasites. 

In New South Wales, where my work kept me during the time among 
the orange trees chiefly, the species of CoccinelUds found preying upon 
Lecanium were far more numerous. I will mention but a few, which 



10 REPORT ON PARASITES AND PREDACEOUS INSECTS. 

are always present in large numbers with the black scales. These are: 
Orcus australasia, Rhizohius ventralis, R. hirtellus, C ryptolxmus Mont- 
rouzieri, and the larva of the Thalpochares moth, which alone is able to 
free whole trees in a very short time. It is only upon bushes or young 
trees generally covered with large numbers of ants, which prevent the 
predaceous insects from coming near, that the black scales become 
numerous. Upon old trees these coccids are but rarely found in num- 
bers, and if so, only upon an occasional branch, which is speedily 
cleaned again by the numerous predaceous insects preying upon them. 

The red scale {Aspidiotus aurantii) is, perhaps, aside from Mytilaspis 
Gloverii and Chionaspis cltri, the most numerous coccid upon citrus 
trees in Australia, and in fact is at present the most injurious to citrus 
trees in that country; but its progress is checked by its natural enemies. 
Australia is in possession of more than enough natural enemies to keep 
this coccid in check with ease, although nearly all these are preyed upon 
by parasites. To spray or fumigate to kill the red scale would also mean 
the destruction of the numerous beneficial insects, and those that were 
not killed outright would mostly leave the orchard in search of other 
food, and the consequence would be that in a few months the trees 
would again become infested, with but few enemies present, and the 
scales would do great damage unless " the spray is again applied." 

As it is, at the present time in Australia, orange and lemon trees are 
often planted in almost any locality, without regard to the situation, 
condition of soil, drainage, climate, and other conditions. The conse- 
quence is that some of these orchards become diseased, presumably 
from the elfects of the red scale, and, as is the case in the Gorden dis- 
trict, near Sydney, one tree after another will succumb. An examina- 
tion showed that these trees had been planted in heavy, cla_vey soil, 
without any drainage, and were invariably destroyed by the so-called 
" foot-rot." The fact is, that if an orange or lemon orchard, as the case 
may be, is left for years without any attention whatever, the weeds 
allowed to grow, and planted in an unsuitable location or soil, before 
very long the leaves become yellow and drop off slowly, and in time the 
remaining green leaves become covered with red scales, since, as is 
always the case, the predaceous insects preying upon this scale will not be 
found on such trees, as they prefer those with dense foliage and shade. 
Such trees may thus linger for months, or even years, before dying, and 
may even again recover if proper attention is given them. In one of 
such orchards, of several acres in extent, but a lew living twigs covered 
with red scale were found, yet not a single one of the many predaceous 
insects preying upon them could be noticed. In another instance, an 
orchard of some eight or ten acres and about thirty-five years old^ 
the proprietor of which always supplied sufficient manure and kept 
the ground cultivated, during the whole time of its existence had been 
infested with red as well as other scales, and yet but a very few trees 
along the border of one side could be found that showed any traces of 
such. The Avhole orchard during the thirty-five years had never been 
pruned or sprayed, nor even had the trunks ever been washed. Numer- 
ous dead limbs were present, the stems and limbs partly covered with 
lichens, and yet I did not meet with a finer lot of trees in Australia — 
such glossy, deep-green foliage, abundance of fruit, and so free from 
scale. 



REPORT ON PARASITES AND PREDACEOUS INSECTS. 11 

A large number of predaceous insects were found preying upon the 
red scale in Australia. Of the most numerous were Orcus chalybeus, 
Orcus australasia, and Rhizobius satellus. Aside from these, numerous 
other species of Rhizohiids were found preying upon this scale, and many 
species of Scymnids, all of which were sent here. In my report all of 
these are treated separately. 

On my visit to Los Angeles and Santa Barbara in the beginning of 
September, Orcus chalybevs were found at Los Angeles, where this species 
was liberated upon the red scale, in such numbers that we can reason- 
ably hope they will have increased by next April, so that we may dis- 
tribute them throughout many orchards. 

The condition in which the insects liberated by you upon the olive 
scale were found was even better than I had expected. The species 
present were Orcus chalybeus, 0. australasia, Rhizobius ventralis, and R. 
debilis. Without doubt other species sent to and libei'tited by you will 
appear in large numbers next spring. It is im])ossible to find, within a 
couple of hours' search, all the species present in a large orchard. Orcus 
australasia and Rhizobius debilis are feeding upon the pernicious scale 
(Aspidiotus perniciosus) at Alameda, where they Avere liberated by Mr. 
Craw, who at the same time left a number of 0. cluilybeus upon these 
coccids; but these have all disappeared, though, positivel}', not to die. 
They will be found upon Lecanium or Chionaspis in time. I have never 
found this insect feeding upon Lecanium in Australia, and did not 
expect it would feed upon L. oleie with you; but this will only show 
that a coccid-feeding ladybird, if at liberty, will most always find its 
food for future generations, and no doubt most of the species liberated 
here will be found again in numbers uj)on some scale. 

In regard to the two species of Orcus we now possess, they were found, 
if my observations in the field are correct, to be two-brooded in Australia, 
the mature insects hibernating during winter. The Rhizobius are much 
faster in breeding, and I estimate about six broods per year. The larvse 
of these, although not numerous at the time, were found in midwinter. 

These insects here, with but few enemies, should increase about fifty- 
fold with each brood, and from one female of Orcus we should expect 
about 2,500 beetles at the end of the season, under favorable circum- 
stances; while of Rhizobius, with six broods, upward of 15,000,000,000 
beetles could be expected, and these figures will not be much out of the 
way in your orchard, where there is an unlimited supply of food. 

On a day when the temperature reached above 100° F. in the shade 
in Australia, the number of Orcus chalybeus upon each orange tree could 
be estimated, as all the beetles came down on the stems near the ground, 
which was a beautiful sight for an enthusiastic bug-hunter, and from 
175 to 300 beetles were collected on each stem; but the larvae of the same 
upon the trees were probably ten times as many. It should be under- 
stood that these trees are never sprayed. 

Some 1,500 difierent beneficial ladybirds are known at present in the 
world, and more than half of these will feed upon scale insects. We 
should do our best to import as many of these as possible, and at the 
same time guard against any new importations of coccids. 

It is not that we should exterminate our scale insects — this is a mat- 
ter of impossibility even with the best of natural enemies or parasites, 
and would be contrary to nature; but we can, with the proper natural 



12 REPORT ON PARASITES AND PREDACEOUS INSECTS. 

enemies, keep these insects in check to such an extent that they will 
not injure our trees, and fruit growing will be possible for all time to 
oome. 

Respectfully yours, 

ALBERT KOEBELE. 

Alameda, Cal., November 14, 1892. 



REPORT ON PARASITES AND PREDACEOUS INSECTS. 15 



REPORT ON CONDITION OF NEWLY INTRODUCED SPECIES 

IN CALIFORNIA. 



To B. M. Lelong, Esq., Secretary, and to the honorable State Board of 
Horticulture: 

Sir: In accordance with letter of instructions of August 28th, to pro- 
ceed with Mr. Albert Koebele to Los Angeles, San Gabriel, Orange, and 
Santa Barbara Counties, and make an inspection and report upon the 
condition of the beneficial insects that have been placed there, and which 
were sent over by Mr. Koebele from Australia during his recent mission 
to that country, having completed said examination, I beg to herewith 
submit the following report: 

On August 31st, Mr. Albert Koebele and I visited the orange orchard 
of Albert F. Kercheval, at Los Angeles, where the first colonies of lady- 
birds from Australia were placed, and which arrived last winter and 
spring. Besides ourselves there were present John Scott, Horticultural 
Commissioner of Los Angeles County; D. W. Coquillett, Special Agent 
of the Department of Agriculture; Henry W. Kruckeberg, editor " Rural 
Californian;" Col. J. R. Dobbins, A. Scott Chapman, Esq., of San Gabriel, 
and others. 

It was at this place that the beetles of the first shipment were placed. 
These arrived in very feeble condition. Mr. Koebele says that they 
probably hibernated in Australia, and possibly had deposited their eggs 
before he captured them. However, after a careful examination of this 
place we found beetles, eggs, larvae, and pupae of the steel-blue ladybird 
{Orcus chalyheus). Insects of later importations were received in good 
condition, and upon our visit Ave found sufficient of their eggs and pupae 
to justify the assertion that this species has become established at Los 
Angeles. Mr. Koebele says this is the insect that keeps the red scale 
{Aspidiotus aurantii) in check in the orange groves in Australia, not- 
withstanding that a parasite preys on these ladybirds there, which 
destroys fully 50 per cent of their first brood, and about 90 per cent of 
the second brood. Great care was taken not to introduce this parasite, 
which is such a deadly enemy to them. When Mr. Koebele discovered 
that the young of these ladybirds were preyed upon by a parasite, he sent 
only mature beetles to California. Thus it may be safely said, that it 
will only be a matter of time when we shall reasonably hope for the 
rapid increase of these valuable insects, and even better results from 
them than are obtained in Australia. 

In another orchard at Los Angeles where a colony had been placed, 
we found but few beetles and larvae, but enough to show that at this 
place also they had become established. 

On September 1st, Mr. John Scott and Mr. Hiram Hamilton, Horti- 
cultural Commissioners of Los Angeles and Orange Counties, respect- 
ively, and I examined the orchard at Orange where a colony of the 
steel-blue ladybirds you sent Mr. Hamilton had been placed. We found 



14 REPORT ON PARASITES AND PREDACEOUS INSECTS. 

these doing well, and there were plenty of beetles and eggs from which 
small larvffi were hatching and were at work upon the red scale. These 
ladybirds had only been out on the trees sixteen days, and as they are 
breeding there successfully, it is conclusive proof that the earlier impor- 
tations had already deposited their eggs before they arrived. 

On September 2d, Mr. John Scott, Col. J. R. Dobbins, of San Gabriel, 
Mr. Koebele, and I inspected the Dobbins orchard at San Gabriel, where 
one of the first colonies of these insects was placed. These, too, arrived 
in very feeble condition, and in fact, hardly any survived the trip. 

A later importation, which you sent Mr. Chapman, arrived in good 
condition, but as they were liberated on large trees they had no doubt 
flown over the orchard, where they will appear later on. 

On September 3d, Mr. Koebele and I visited Hon. Ellwood Cooper's 
orchard at Santa Barbara. It was at this place that several species 
were liberated in the open orchard immediately upon their arrival. 
We found four species that have become well established, viz.: Orcus 
chalyheus, Orcus australasia, Rhizobius ventralis, and a small Scyvinodes. 
Of all these we found beetles, eggs, larvie, and pupae. The trees upon 
which they were placed are infested with black scale, and they are feed- 
ing upon it. Mr. Cooper placed these insects in an orchard where he 
considered the conditions as to temperature and protection from the 
prevailing winds favorable for their colonization. 

On September 9th, I visited the orchard at Haywards, Alameda 
County, where Mr. Koeljele had himself placed several species. I 
found beetles of the Orcus anstrnlasia and Rhizobius ventralis, appar- 
ently doing well. At this place a muslin tent was placed over a lemon 
tree where the Thalpochares coccaphagus, an enemy to the black scale, is 
being bred. 

I placed a small colony of Orcus australasia and JUiiznbius ventralis 
upon trees infested with pernicious scale in Alameda, and upon exami- 
nation two days ago we found beetles, larva% and i)upie. The larvffi 
have fed upon the scale and passed through their molts into well- 
developed pupie, ])roving conclusively that they will prey upon it. 

The new Australian ladybird, Novivs Koebelei, of which only three 
live insects were received last A])ril, and which were bred in the office, 
have multiplied very rapidly, and from these many thousands have 
been distributed. The successful colonization of this ladybird has fully 
sustained Mr. Koebele in the statement, that they are even better than 
the Vedalia cardinalis in keeping the cottony cushion scale in check. 
The colony of fifty which you gave Mr. John Scott, of Los Angeles, 
have done well, and from those he has distrilnited several thousands, 
and is well pleased with their work. 

From the foregoing it will be seen that five new species of beneficial 
insects have l)een successfully introduced and become established in the 
State, and while we cannot expect much benefit from them tliis year, as 
time is required for those introduced to breed, I am confident that next 
spring and summer they will be abundant, and colonies can then be 
furnished to growers throughout the State. 

The unprecedented success of the Vedalia cardinalis has caused fruit 
growers and others to expect immediate and similar results from all of 
the new insects, but as the Orcus chalyheus and Orcus australasia have 
only three generations, their increase Avill be slower; however, I feel 
satisfied that the final result will be equally as satisfactory as with 



REPORT ON PARASITES AND PREDACEOUS INSECTS. 15 

the Vedalia. For the present, orchardists having trees infested with 
red_ scale should not neglect spraying or fumigating this fall, so that 
their fruit will be bright and merchantable, and prevent injury to the 
trees for the present from the pernicious effects of the pest. 
Mr. Koeble has reviewed this report, and concurs in the same. 

ALEXANDER CRAW, 
Entomologist and Quarantine Officer. 
San Francisco, Cal., September 10, 1892. 



1) 



